Metal vapor arc rectifier



Aug. 30, 1932. J, as 1,873,957

NIEfI'ALv VAPOR ARC RECTIFIER Filed Nov. 17, 1926 2 Sheets-Sheet 1 ,49 2a 11 l f I ,1; h

ZZiV/A KAUVA V/2l W2 IN VENTOR i s ATTORNEY Aug. 30,1932. J; EGLl 1,873,957

METAL VAPOR ARC RECTIFIER Filed- Nov. 17, 1926 ZSheets-Sheet 2 INVENTOR nrromvz one rectifier Patented Aug. 30, 1932 aroma 'EGLI, or CAMDEN, NEW JERSEYQAS srenon, BY MEsNE ASSIGNMENTS, 'ro ALLIscnALMEEs MAEUEAcrUEING COMPANY, OF MILWAUKEE, Wisconsin] A con:

ronA'rron or DELAWARE METAL vAroE AEc EEcrIEIEE Application filed November 1 7, 1926. Serial No. 148,873. 7

This invention relates to metal vapor arc rectifiers and more particularly to a new method of operatingsame.- v I c J Mercury-are rectifiers hitherto known for converting alternating to direct current are subject to various troubles of which short circuits between theiron electrodes are the most dangerous Ones. able, however, are the conditions in high power mercury arc rectifiers such as used for more than 500 amperes due to the immense development of mercury vapor for which a comparatively small condensing surface" is available and'due to the intensive but diffuse ionization. V

Apparently the simplest way to overcome these disadvantages would be to use at least 7 for each phase of the polyphase current. However, it would then be necessary to provide independent evacuating means for each single rectifier, for it would not be advisable to provide only one vacuum pump set for the whole rectifier unit on account of the fact that it would be absolutely necessary to insert insulating piecesin the common vacuum piping in order to avoid short circuits between 'the iron electrodes. This is, however, not yet practicable in such a way that couldoberelied upon. It'would, further, be disadvantageous if not practicallywimpossible to guide the vacuum piping common to' all single rectifiers through the mercury electrodes into the interior of the vacuum vessels, for the branches of the-vac uum pipe would terminate inside the rectifiers directly in a place where most of the mercury vapor is developed so that too much mercury would be sucked in by thepump. J

According to my inventiona number o rectifiers, at least one for each phase of the polyphase current source, are combined to make up one polyphaserectifier unit and the general object of my invention is to connect these single rectifiers' electrically in such a manner that short circuits between the iron electrodes of the single 're'ctifiers are entirely prevented and that all rectifiers of the same polyphase unit can be connected to only one vacuum'pump or pump set without inserting insulating pieces in the vacuum piping. This Especially. unfavoriron electrodes is obtained by connecting each phase of the polyphase current source with at least one mercury electrode while all iron electrodes will be connected to the neutral point of said .11 current source through a direct current netin work. i i

A further object of my invention is tojprovide only one iron electrode common to all mercury electrodes and to connect the common iron electrode'with the neutral pointof a polyphase current source over a circuit to be supplied with direct current while each phase of the polyphase current source is connected at least with one mercury electrode. Still a further object of my invention is to provide'the common iron electrode with channels or ducts by means of which a connection between the single 'arc chambers, in

which the mercury electrodes are located, and the evacuating means can easily be obtained. "i Other and further objects of my invention will become readily apparent to persons skilled in the art from a consideration of the following description.

In the accompanying practical embodiments of the invention are shown. v

Fig. 1 illustrates, diagrammatically, one way of carrying the invention into effect.

Fig. 2 is a similar view showing the use of Q0 a common iron electrode.

Fig. 3 is an elevation, partly in section, showing a further modification; and

Fig. 4 is atop plan view of the modification shown in Fig. A

Referring to the drawings, and more partic'ularly to Fig. 1 thereof, 10 indicates a three phase current source which can be a three phase generator or a corresponding transformer. ,Three evacuated metal vessels be 11, and 13 equipped with iron electrodes 31,.32 and 33 and mercury electrodes 14,15 and 16" r espectively are provided one for each phase of the jcurrent'source 10. Themercury 3 electrodes v1 1, 15, and 16 are connected to'one phase each of the current source 10, and the 3 1, 32 and 33 are in connection with the neutral point of said current source over the circuit 18 which should besupplied with direct current. The iron electrodes 31,

drawings, several i5 32 and 33, forming the covers of the metal vessels 11, 12 and 13, each have a suitable opening or hole 30 by means of which a connection with the interior of the vacuum vessels and the evacuating means (not shown in the drawings) will be obtained over the branches 29 of the vacuum pipe 20 which leads to the evacuating means.

n Both kinds of electrodes, the iron elecy trodes 31, 32i'and 33 andthe mercury elec-.

trodes 14, 15 and 16 as well, are insulated from the vacuum vessels 11, 12 and 13 by suitable insulators 21. Each vessel or are chamberis equipped with a movable ignition and a sta tionary excitation electrode 22 and 23 respec tively which may be operated in known manner by means of a transformer 24.

In so connecting up and arranging the electrodes, the rectifier, according to my ln'ven- .tion, once ignited will produce a direct current in the circuit 18 due to the well known valve action within the vacuum vessels.

The advantages obtained by this new arrangement are obvious. Short circuits between the iron electrodes are entirely eliminated and smaller .vacuum vessels can be, used to make up one polyphase unit thus facilitating the cooling of the same which is especial- 1y desirable in high power mercury arc rectifiers. p

Instead of using separate iron electrodes, only one iron electrode common to all mer cury electrodes may be employed. Such modification is illustrated in Fig. 2 in a similar point of the three phase current source 10 over the circuit 18 to be supplied with direct our- 7 rent. Ducts or channels 19, suit-ably arranged in the iron electrode 17 connect the vessels 11, 12 and 13 with a pipe 20 which in turn is in connection with a vacuum pump or vacuum pump set not shown in the drawings. In

this modification also the iron electrode 17 and the mercury electrodes 14, 15 and 16 are insulated from the vacuum vessels as indicated by 21. i v

. As shown in Figs. 3 and 4, the vacuum vessels containing the mercury electrodes are arranged in a circle around the common iron electrode 17 The electric connections which .are similar to the ones shown in Fig. 2, are not shown inthese figures in order to illustrate clearly that various arrangements can be made without departing from the spirit of the invention. v

Certainly thefvacuum vessels can be arranged in various ways. They can be placed one after the other or beside each other in a row or opposite to each other in several rows or in a circle or in any other manner.

The outer surface of the vacuum cylinders 11,12 and 13 may be ribbed or corrugated which a-cooling medium circulates, Still further, meansforjair, water or oil cooling may be arranged around the mercury elec-' trodes. i I 7 While I have described what I consider the preferred forms of my invention, I do not limitmyself to the forms shown but claim as my invention any method and device coming within the scope vof theappended claims.

What I claim as new is V I 1. In a vapor electric rectifier aiplurality of containing vessels, a mercury cathode in each vessel, and acommon anode, a source of polyphase current situated, outside said vessels,'the phases of said current source being connected respectivelyto the respective cathodes,and the neutral point of said current source in connection with the said anode over a circuit to be supplied with direct current, and means forevacuating said vessels placed outside the vessels and'common to all of them, ducts arranged within the anode which are adapted to connect each vessel to the said evacuating means.

2. A metal vapor arc rectifier comprising in combinationa plurality ofmetal cylinders, a mercury cathodewithin each cylinder, and an anode common to all said cathodes, a source of polyphase current situated outside the cylinders, the phases of said current source being connected respectively to the respective cathodes, and the neutral point of said current source connected to theanode through a direct current network, means for evacuatmg said cylinders and common to all of them arranged outside said cylinders, and a plurality of passageways inside the anode, adapt- 7 ed to connect each cylinder with the said evacuatingmeans.

3. In a metal arc rectifier a plurality of cathodes, each of said cathodes being located in an evacuated metal container, an anode common to all of said cathodes, a source of polyphase current, the phases of said current source being in connection respectively with the respective cathodes, and the neutral point of said current source connected to the said anode through a. direct current network,

means for causing an arc to pass between the anode and the cathodes, and means for exciting said cathode in each container, means for evacuation of said containers arranged outside the latterv and common toall of them,

and channels within said anode adapted to connect each metal container with said evacuating means, said containers being provide with a ribbed outer surface which is adapted to carry off the heat developed in the interior of said containers during operation.

4. In current-rectifying apparatus, means providing an operating chamber, an electrode associated with said means, and means providing for fluid-evacuation of said chamber by way of said electrode. c

5. In current-rectifying apparatus, a plurality of current-rectifying units comprising the same, electrode means associated with and common to said units, the said electrode means comprising means providing for fluidevacuation of the said units by way of said electrode means.

6. In current-rectifying apparatus, a plurality of current-rectifying units comprising the same, and an operatingelectrodefor and common to each of said units. r

7. In current-rectifying apparatus, a plurality of current-rectifying units comprising the same, means common with respect to said units and providing an operating electrode for each of the same, and means common with respect to said units and providing for fluidevacuation of the same by way of said electrode means. 7

8. In current-rectifying apparatus, a plurality of current-rectifying units comprising the same and positioned in such wise with respect to themselves as to constitute a group of such units, and means disposed substantially centrally of such group and being common with respect to said units and comprising an operating electrode for each of the same. I

40 9. In current-rectifying apparatus, a plurality of current-rectifying units comprising I the same and positioned in such wise with respect to themselves as to constitute a group of such units, means disposed substantially centrally of such group and being common with respect to said units and providing an operating electrode for each of the same, and means common with respect to said units and providing for fluid-evacuation of the same i by Way of said electrode means.

In testimony whereof I aflix my signature.

' I JOHN EGLI.

I CERTIFICATE OF CORRECTION.

Patent No. 1,873,957. August 30, 1932.

JOHN EGLI.

it is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, line 113, claim 2, strike out the words "arranged outside said cylinders" and insert the same to follow "cylinders" in line 112; and line 113, strike out the comma after "anode"; and that the said Letters Patent should he read with these corrections therein that the same may eonform to the record of the case in the Patent Office.

Signed and sealed this 10th day of January A. D. 1933.

N (heal) Acting Commissioner of Patents. 

